Designing Flexible Circuits

Chapter 0 Course Introduction

• Course Objectives
• Intended Audience
• Course Structure
• Course Content

Chapter 1 Flexible Circuits

• What Are Flexible Circuits
• Origin Of Flexible Circuits
• Advantages Of Flexible Substrates
• Applications
• Industrial Applications
• Automotive
• Computer Peripherals
• Consumer
• Instruments
• Medical
• Military
• Telecom
• Types Of Flexible Circuits
• Flex
• Rigid-Flex
• Flexible Coil
• Main Benefits Of Flexible Circuits
• Thermoelectric
• High Reliability
• Repeatable installation.
• Harsh environments.
• Long duty cycles.
• High vibration.
• Superior Packaging
• Flex Versus Wiring Harness
• Flex Versus Printed Circuit Board
• Advantages Of Rigid-Flex
• Double side component mounting.
• Improved impedance control.
• Vibration resistance.
• High mass component mounting.
• Chapter 1 Review Questions
• Chapter 1 Review

Chapter 2 Design Options

• Association Connecting Electronics Industries
• Single-Sided Flexible Circuits
• When To Use Single-Sided Flexible Circuits
• Double-Sided Flexible Circuits
• When To Use Double-Sided Flexible Circuits
• Multi-Layer Flexible Circuits
• When To Use Multi-Layer Flexible Circuits
• Rigid-Flex Flexible Circuits
• Rigid-Flex Features
• Multi-Layer Not Plated Flexible Circuits
• Design Options
• More Design Options
• Terminators
• Connectors
• High Density Connectors
• Fingers
• Pins
• Types Of Pins
• Flexible Coil Circuits
• There are three basic types of flexible coil circuits.
• Simple, flat coils with wire leads.
• Coils laminated inside flexible circuits.
• Rim coils that are built up along the Z-axis.
• Design Considerations For Rigid Flex
• More Design Considerations For Rigid Flex
• Benefits Of Using A Stiffener
• More On Using A Stiffener
• Stiffener Material
• Stiffener Hole
• Through Hole
• Wiring Hole
• Vias
• Pads
• Pad Fillets
• Surface Mount Access
• Chapter 2 Review Questions
• Chapter 2 Review

Chapter 3 Flexible Circuit Materials

• Components Of Flexible Circuits
• Base Material
• Adhesive
• Metal Foil
• Characteristics Of Flexible Circuit Laminates
• Dimensional Stability
• Thermal Resistance
• Tear Resistance
• Chemical Resistance
• Low Moisture Absorption
• Low Cost
• Types Of Base Material
• Comparing Polyester And Polyimide
• Base Material Properties
• Types Of Adhesive
• Acrylic Adhesive
• Butyral-Phenolic Adhesive
• Epoxy Adhesive
• Polyester Adhesive
• Polyimide Adhesive
• Adhesive Properties
• Types Of Copper Foil
• Copper Foil For Printed Wiring Applications
• Electrodeposited Copper
• Wrought Copper
• Electroplated Copper
• Circuit Lay Out To Conserve Material
• Nesting
• Chapter 3 Review Questions
• Chapter 3 Review

Chapter 4 Flexible Circuit Requirements

• Steps To Defining Flexible Circuit Requirements
• End Product Requirements
• Reliability Requirements
• Operating Environment Requirements
• Operating Temperature Ranges
• Package Configuration
• Mechanical Requirements
• Electrical Requirements
• Location Of Components
• Assembly Method
• Electrical Testing
• Mechanical Testing
• Create A Demonstration Circuit
• Build A Flexible Circuit Mock Up
• Steps To Build A Flexible Circuit Mock Up
• Create CAD Data
• Additional Steps
• Chapter 4 Review Questions
• Chapter 4 Review

Chapter 5 Design Guidelines For Flexible Circuits

• Flexible Circuit Versus Hardboard
• Tolerance Settings In Flexible Circuit Design
• Use Of Multiple Datum
• Guidelines For Dimensioning
• Tolerances
• Standard Design Recommendations For Tolerances
• Conductor Width, Thickness, And Spacing
• Designing With Copper
• Weight Is A Cost Factor
• Cost Impact Of Layer Count
• More On Cost Impact Of Layer Count
• Manufacturing Cost Of A Flex Circuit
• Manufacturing Steps
• Ways To Minimize Circuit Cost
• Controlling Impedance And Electrical Noise
• Ways To Control Impedance And Electrical Noise
• Service Loops
• Staggered Length Circuits
• Forming
• Forming Factors
• Bend Radii
• Bend Ratio
• More On Bend Radii
• Copper Plating
• Stressors
• Time And Temperature
• Conductor Routing
• Sharply Angled Conductors
• How To Improve Flexibility And Bend Radius
• Minimum Bend Radius
• Reduce Thickness In The Flex Area
• Make The Circuit Robust To Withstand Flexing
• More On How To Withstand Flexing
• Even More On How To Withstand Flexing
• Ground Plate Design
• Pads, Holes, And Annular Rings
• General Requirements For Pads, Access Holes And Annular Rings
• Design Requirements For Pads, Access Holes And Annular Rings
• Sizing Vias
• Fillets
• Hold-Down Tabs
• Plated Through Holes
• Covercoating
• Sizing Coverlayer Openings
• Tear Resistance
• Ways To Prevent Tearing
• Trimming
• Chapter 5 Review Questions
• Chapter 5 Review

Chapter 6 Light Emitting Diodes In Flexible Circuits

• Light Emitting Diodes
• A Light Emitting Diode (LED) is based on the semiconductor diode.
• Light Emitting Diodes have been primarily concentrated in consumer electronics markets.
• Benefits Of Light Emitting Diodes
• Types Of Light Emitting Diodes
• Light Emitting Diodes Today
• The Effect Of Temperature
• Thermal Management
• Material And Light
• Chapter 6 Review Questions
• Chapter 6 Review

Chapter 7 Conclusion